sorry to hear stuff got spoiled, but can I ask where you are in the conspiracy quest? without knowing where you are it's a little difficult to help.
no need to worry about not giving a screenshot, I wasn't expecting one and thought you'd just type it like people usually do lol. (not complaining tho screenshots are almost always helpful.) and another question, have you completed the Bareshade expansion and Mythshore storylines?
also what happens when you try to go to the murcad cave with Scar? does he just not show up, does the game give a warning does it say you need something to progress when at the cave? and have you done the eavesdropping Gunnar and Everett's conversation mini event?
what happens with the choices and what are the choices with the warning? because that should be right before you start the event to progress the conspiracy storyline is and there shouldn't be anything stopping you from just saying your ready and getting into the event.
also just a sidenote, try both at day and night for whatever option you pick in case it's that. not saying it is but I've fucked up and completely forgotten some stuff is based around the games time cycle and struggled for like any hour lol.
"under the cover of night" just means after 20:00 but before 0:05 in game time lol. and yeah, but rereading your last thing, have you done the thing where you explore the cave with Scar alone? because if you haven't my bad I completely misunderstood where you were. and the option should show up at the cave as "meeting point"
and no one has met yet her lol. she's just spoken a lot about by over half the NPC's in game involving Northcrest XD